A Lincoln County Sheriff’s Department employee is charged with stealing after an internal investigation showed she embezzled at least $25,000.

The St. Louis Post-Dispatch reports that 47-year-old Helen D. Mershon of Troy is jailed on a $75,000 cash-only bail. Officials said she did clerical work at the jail. It’s not immediately known if she has an attorney.

Sheriff John Cottle said in a press release that until he stepped in this January, the employee operated with no supervision. The release says the theft discovery was made while performing internal reviews of different divisions in the department.

Cottle says he has put in safeguards to prevent such thefts from happening again.